1. Field of the Invention
The present invention relates to a bandpass filter (BPF) for filtering a signal of ultra wide band (UWB).
2. Description of the Invention
Generally, UWB (Ultra Wide Band) communication technology is capable of transmitting a large quantity of data through a broad frequency spectrum at a high data transmission rate with low power consumption within a limited range. The UWB communication employs an ultra wideband signal having a broad frequency bandwidth in the range of GHz for transmitting a predetermined data, and can transmit at a high data transmission rate from 100 Mbps to 1 Gbps. The UWB communication is expected to solve the communication frequency shortage problem because it can transmit data on instantaneous short pulses at a high data transmission rate through a broad frequency spectrum.
In addition to the advantage of the high data transmission rate, the UWB communication still has another merit in that its power consumption is at most 1/10 of a power necessary for implementing communications in communication products such as cellular phones and wireless local area networks (WLANs). The UWB communication is widely used for a wide variety of terminals such as cellular phones, personal communication services and wideband code division multiple access (WCDMA), and it is necessary to miniaturize parts for BPFs employed by the UWB communication.
There are available wide ranges of BPFs used for the UWB communication. However, there is a problem in the most of the BPFs manufactured with microstrip patterns being formed on a surface of a dielectric substrate in that the BPF has a narrow stop band and is too big in size for application in products.